BETA Electronics RC33 II Series Installation And Operating Instructions

Defrost action defrost end optimization
Evaporator Evaporator
defrost END
temperature temperature
(the evaporator temperature
Probe 2 Probe 2
reaches the dEt value)
dEt dEt
dEt-2
The heater
melts the ice
Heater ON
Heater ON
time
the defrost duration won't be longer than ddt

4.40 FAN parameters

Param. Description
Default fan operating mode.
Fod
0: switched off; 1: thermostat mode, switched on if ( FSr < probe2 temperature < FSt ); 2: switched on.
Fan operating mode during the defrost action.
Fdd
0: switched off; 1: thermostat mode, switched on if ( FSr < probe2 temperature < FSt ); 2: switched on.
Fan operating mode when the compressor is switched off.
Fdc
0: switched off; 1: thermostat mode, switched on if ( FSr < probe2 temperature < FSt ); 2: switched on.
FSr Fan start temperature. If the fan is on thermostat mode, it is switched on if the temper. of probe 2 is higher than FSr.
FSt Fan stop temperature. If the fan is on thermostat mode, it is switched off if the temper. of probe 2 is higher than FSt.
FtH Fan temperature hysteresis for thermostat mode. Delta temperature value to avoid regulation oscillations of the fan.
Fan start delay at power on and after defrost.
FSd
At the power on of the RC33 and after the defrost end, the fan is switched off for FSd minutes.
Fan output if thermostat mode selected
FSr-FtH
FSr FSt-FtH
on
off
temperature probe 2

4.50 Various parameters

Param. Description
External contact digital input operation (ex dio).
Negative value: digital input signal is active if external contact is closed. Positive value: dig. input is active if contact is opened.
Eio 0: disabled ; ±1: cold room's door open, switch off the fan; ±2 : door open, switch off fan & compressor ; ±3: St2 is the
desired temperature (instead of SEt); ±4: start defrost (for another defrost start command, de-activate and activate again the
ext.contact); ±5: toggle to stand-by mode (the off state is not stored in memory); ±6: external alarm, switch off all the relays.
Eid Ext. contact input delay (ex did). From the activation of the external contact, RC33 waits Eid minutes to start the Eio function.
Prt Probes type. 0: both probe input lines are able to read 10Kohm NTC temperature sensor; 1: 5Kohm NTC; 2: 990ohm PTC.
Probe 2 analog input enabling. It is possible to disable the evaporator probe measure. 0: probe 2 disabled; 1: enabled.
Pr2
When probe 2 is disabled: defrost actions will be ddt long, the fan in thermostated mode will be switched off.
rES Display temperature resolution. 0: the temperature is shown in tenths of degrees; 1: temperature without decimal point.
Temperature unit measurement. 0: Celsius degree; 1: Fahrenheit degree.
Unt
(changing Unt value, RC33 doesn't match any parameter. Rearrange temperature param. values in order to adjust the control)
oF1-2 Temperature probes calibration. To modify the temperature value measured by the probe 1 and by the probe 2.
Temperature displayed. 0: temperature probe 1 (cold room);
tdi
Pressing the "Up" key it is possible to display for a few seconds the temperature measured by probe 2 and then 1.
Update temperature filter. Different averages are performed to avoid noise spikes on the probes measurements.
utd
0: filter disabled (3 measures displayed per seconds); 10: the temperature average is evaluated on the longest time span.
Long pushing Function configuration.
LFc
0: pushing for 5s the "Function" key start/stop defrost; 1: pushing for 5s the "Function" key toggle on/off the RC33 (stand-by).
PSS Password setting. It is possible to set a password to access on the 2nd menu parameter. 0: password request disabled.
Low voltage sensing. In order to improve the functioning, the controller continuously verifies the power supply voltage.
LVS
0: function disabled; 1: short voltage drop is not detected (min sensitivity); 10: short voltage drop is detected (max sensitivity).
Slave device number address. It is the address of the controller in a bus network with ModBus-RTU protocol.
nAd 0: serial port is disabled. When a key is pushed or in programming mode, RC33 does not always answer to the serial port.
(after having changed this value, the RC33 must be restarted)

5.00 Troubleshooting

Message Description, cause
Hit The measured temperature of probe 1 (cold room) is higher than the (AHi+0,4)
parameter value. If AtP=1, the temperature is higher than (SEt+AHi+0,4).
Lot The measured temperature of probe 1 (cold room) is Lower than the (ALo-0,4)
parameter value. If AtP=1, the temperature is lower than (SEt-ALo-0,4).
ALE Extern alarm. When Eio=±6 and the external contact is active.
PF1 The probe input line 1 (cold room) is opened/disconnected or short circuited.
The measured temperature is out of the range.
PF2 The probe input line 2 (evaporator) is opened/disconnected or short circuited.
The measured temperature is out of the range.
PrF The probe input line 1 + 2 is opened or short circuited.
Memory error. The parameter list could be corrupted. The fridge control is not assured.
EEP
Immediately check every parameter value, save the correct value, restart the RC33.
LoV Low voltage detection on the power supply. Check the voltage value, noises (par. 1.20).
dOP Door opened. When Eio = ±1 or ±2 and the external contact is active.
OFF The controller is going to switch off the outputs and display (stand-by mode).
Note: if PF2 error, the defrost
dEo
will be performed every dPt
hours for ddt minutes, without
Residual ice on the
control of dEt and dEo.
defrost
The heater
evaporator makes the
END
melt the ice
temperature to drop
time
the defrost duration won't be longer than ddt
-50 .. FSt °C
FSr .. 150 °C
0.1 .. 20 °C
0 .. 120 minute
Note: If thermostat mode operation is set for the fan (Fod=1 or
FSt
Fdd=1 or Fdc=1), in case of PF2 error the fan is switched off.
off
0 .. 60 minutes
-10 .. 10 °C
1: temperature probe 2 (evaporator); 2: SEt value.
0 .. 999
0 .. 247
Output
The outputs don't change.
*The controller starts to save the alarm data (haccp).
The outputs don't change.
*The controller starts to save the alarm data (haccp).
All the outputs relay are switched off.
Compressor operation is according to PEc.
Other outputs don't change.
The defrosts are performed by time; no checking dEt, dEo.
The fan is switched off (except when fan is set On).
See PF1 + PF2 output.
Not predictable.
All the outputs are switched off.
Eio=±1, switch off the fan output;
Eio=±2, switch off compressor and fan output.
All the output relays are switched off.
Installation and
Range Default
operating instructions
0 .. 2 2
0 .. 2 0
Up
0 .. 2 1
-45 °C
2 °C
1 °C
0 m
Down
RC33 II Series
Range Default
Electronic refrigeration
controllers
-6 .. 6 0
0 m
0 .. 2 0
0 .. 1 1
1.00 GENERAL DESCRIPTION AND INSTALLATION NOTICE
0 .. 1 0 The RC33 models are controllers specifically designed to manage ventilated refrigerating units, for positive or negative temperatures. The
controllers have 2 analog inputs for ntc/ptc temperature probes (room and evaporator), optionally a digital-input for an external switch and 3
0 .. 1 0
relay outputs for compressor (16A), fan (5A) and defrost heater (8A). It is designed to perform defrost by electrical heater or hot-gas; the
0 °C
defrost end may be based on fixed time or by the evaporator temperature. RC33 detects temperature alarm conditions referred to the main
0 .. 2 0 probe (#1), storing into its memory the last tree events (Haccp feature). Through the TTL port, an external master device can read and write
the RC33 registers, in order to monitor and change its functioning (ModBus protocol over a serial line).
0 .. 10 5

1.10 Installation notice

The installation must be done only by specialized personnel in according to the rules in force in the country where the controllers are used. The
0 .. 1 0
instrument is conceived for controlling and regulation, not for safety function. It must be installed in a place protected from extreme vibrations,
0
impact, water, corrosive gases, and where temperature and moisture do not exceed the maximum rating levels indicated in the specifications.
0 .. 10 1 The same directions are valid for the probe installation. The probe is not waterproof, it should be placed with its head upward, so that drops
would not penetrate into the bulb and damage the sensor. Maintain the length of the electrical wires as short as possible in order to keep the
noise picked by them at low level; otherwise a shielded wire will be needed, and the shield will be connected to the ground.
0

1.20 ELECTRICAL WIRING

We recommend to protect the power supply of the controller from electrical noise, spikes and especially from voltage surges and drops. This
can be easily done following these recommendations:
-separate the power supply of the loads (compressor, heaters, fans) from the power supply of the controller. This alleviates problems related to
voltage dips that can arise during the switch-on of the loads, that may disturb the controller's microprocessor causing unexpected resets.
-the cables of the probes and the ones of the controller supply or the loads must be separated, to reduce spikes and noise on the sensor. This
improves the stability of the reading and it also makes the commutation of the device more accurate.

1.30 CRITICAL ENVIRONMENT

For applications in heavy industrial environment these rules should be followed.
- After having identified the source of noise spikes, it is recommended to apply a line filter to the source in question of the type specifically
designed to solve EMC (Electromagnetic compatibility) related problems. Sometimes it may be sufficient an RC type filter, also called
«snubber» , connected in parallel to the external relay coils, or circuit breakers.
- An independent power supply should be used to power the device in extreme conditions.
ATEX reserves the right to make changes without further notice to any products herein to improve reliability, function
or design. ATEX does not assume any responsibility for any improper use or application of any product or circuit
described herein. ATEX products are not designed, intended, or authorized to be use as components in systems or
applications intended to support or sustain life, or for any other application in which the failure of the ATEX product
could create a situation where personal injury or death may occur.
Rev.: 19-11-2008 Cod.: 82300.0100.0

- KEYBOARD FUNCTIONS

Enter: to activate the programming mode and to view and to confirm the
new values.
Function: 1) to show the Haccp records; 2) pushed for 5 seconds, to
start or stop manually the defrost (if LFc=0) without waiting dSd, or to
switch on/off the controller (if LFc=1). The off mode, or stand-by, is
stored in memory; 3) in programming mode, to quit the parameters
menu without saving the new values (escape command).
Up: 1) to display, for a few seconds, the probe 2 temperature and,
pushed twice, the probe 1 snap temperature; 2) during the programming
Function
mode, to scroll the parameters menu and to increase the value of the
selected parameter.
Down: 1) pushed together with the Enter key, for 5 seconds, to lock /
unlock the keyboard; 2) during the programming mode, to scroll the
parameters menu and to decrease the value of the selected code.
Light on compressor is running;
Flashing waiting for a time delay to switch on the compressor.
Enter
Light on fan is running;
Flashing waiting for a time delay to switch on the fan.
Light on defrost action is running;
Flashing defrost optimization is running.
The upper left point is flashing in programming mode and is lit on if an external
contact is active (digital input) or during the stand-by mode.
Numbers 1, 2 indicate the current probe temperature shown on the display.
ATEX Industries srl
33078 S. Vito al Tagliamento – PN
Tel.: +39 0434 85183 r.a.
web: www.atex.it - e-mail : beta@atex.it
Italy